(a) Technical Field of the Invention
The present invention relates generally to a paste-bonding mechanism of a corrugated paper making machine, and in particular to a corrugated paper bonding mechanism featuring increased pressurizing area between a core sheet and a surface sheet to enhance bonding strength between the core sheet and the surface sheet.
(b) Description of the Prior Art
FIG. 1 of the attached drawings shows a conventional corrugated paper bonding device, which comprises a primary corrugated roller 10 and a secondary corrugated roller 20 between which a core sheet that is originally a flat-surfaced paper sheet 5a is fed to form corrugation on the paper sheet, which then serves as the corrugated core sheet 5a. A paste application roller 30 applies a layer of paste on a surface of the corrugated core sheet 5a and thereafter, another paper sheet, which serves as a surface sheet 5b, is laid on and bonded to the paste layer of the core sheet 5a to form the finished corrugated paper 5c. Bonding of the surface sheet 5b to the core sheet 5a is done by feeding the core sheet 5a with the surface sheet 5b laid thereon between a pressurizing roller 40 and the primary corrugated roller 10 to induce a pressure between the surface sheet 5b and the core sheet 5a. 
The conventional manner of pressurizing the surface sheet 5b against the core sheet 5a suffers limited pressurizing area between the core sheet 5a and the surface sheet 5b, and very limited time of application of the pressure. This often causes poor bonding strength of the corrugated paper. A conventional solution for such a drawback is to apply a great pressure between the core sheet and the surface sheet, but, as illustrated in FIG. 2, this often causes damage to the surface sheet, such as fracture of fibrous structure of the surface sheet and shows up indentation marks on the surface sheet, eventually reducing fracture strength of the corrugated paper.
Thus, the present invention is aimed to overcome the drawbacks of the conventional devices by providing a bonding mechanism of corrugated paper making machine that improves product quality and increases operation efficiency.